(1) Field of the Invention
The present invention relates generally to a MEMS (Micro Electro-Mechanical Systems) device, and more particularly, to a micro-scale alignment device capable of repeatedly aligning a stage portion relative to a support structure with a relatively high degree of accuracy and precision with up to six degrees of freedom.
(2) Background Information
There is a growing need for fine motion control and positioning at micro and nano scales, such as for the growing number of MEMS applications, including active alignment of fiber optic elements, x-y stages with nanometer level resolution, and machine elements for micro-scale machinery. Also, micro-mirrors, micro-resonators, and manipulation for bio molecules . . . etc will require multi-axis nano and micro-positioners.
Culpepper, in U.S. patent application Ser. No. 10/175,415, filed on Jun. 19, 2002, entitled “Six Degree of Freedom Flexure Stage”, (the ‘415 reference’) which is fully incorporated herein by reference, discloses an adjustable monolithic compliant mechanism. This compliant mechanism includes a stage which may be adjusted by displacing one or more tabs coupled thereto, to provide for controlled movement in six degrees of freedom.
Next generation applications (e.g., fiber optic alignment, optical switching, and the like) will require precision alignment devices capable of being fabricated on a micro- or nano-scale, e.g., as MEMS devices fabricated on a chip-level using many conventional semiconductor fabrication techniques, and which are capable of providing high resolution (i.e., nanometer/microradian) position control with six degrees of freedom (i.e., x, y, z, θx, θy, and θz).
Indeed, as shown in FIG. 1, a lateral misalignment as small as 0.001 mm have been shown to generate insertion losses in fiber optics of 1 dB. Likewise, angular misalignment as small as 0.001 rad (0.057 degree) may result in more than 1 dB loss. Unfortunately, conventional alignment devices typically require actuation along at least three mutually orthogonal axes in order to generate movement with six degrees of freedom. Such actuation, however, does not lend itself to the planar structures typically associated with semiconductor fabrication and MEMS devices. Therefore there exists a need for a micro-scale alignment device configured for fabrication using micro-scale wafer fabrication techniques.